Edwin d



Patented Oct. 19, 1886.

H but Maw, VIM u c (No Model.)

B. D. MOORAGKEN.

UNDERGROUND ELECTRIC CONDUCTOR.

UNITED STATES PATENT OFFICE.

EDVlN D. MCCRACKEN, OF PA TERSON, NEW JERSEY.

srncrrrcn-mon forming part of Letters Patent No. 351,193, dated October 19,1886.

Application filed May [7, 1294. Renewed August. 19, 1886. Serial X0. lllflfifl. (Nu mndvl.)

To all whom. it may concern.-

Be it known that I, EDWIN D. BIOCRACKEN, of the city of Paterson, in the county of Passaic and State of New Jersey, have invented a new and useful Improvemeutin Underground Electric Conductors, of which the following is a specification.

My invention relates to electric conductors which are laid in tubes or conduits underground, the tube or conduit:- being composed of sections joiplcd by couplings, and a large number of con uctors being iuclosed therein.

My invention is more particularly intended for compound conductors, each consisting of a primary conductor andn secondary conductor for induced currents, but may be employed in laying simple cond uctors.

The invention consists in the combination, with t-ubcsr-clions composed olspiral|y-wouud and superposed strips ofpure vegetable paper. the sections being laid with separated ends and connected by coupling-sleeves, of conductor-sections arranged in each tubes-ection, and each having an insulation of spiral- Iywound strips of pure vegetable paper, the conductor-sections in adjacent lube-sections being joined between the ends of thetube-seclions, and a filling of insulating matcrialwithin the tube-sections and coupling-sleeve, in which the conductors are embedded. By such a combination a large number of conductors may be laid in a tube of comparatively small size,aud are effectively insulated by the paper coveriugs,the insulating material in which they are embedded, and the spirally-wound paper of which the tube-sections are composed. The filling of insulating material is put in while in a fluid or plastic state, and penetrates and preserves the paper coverings of the conductors and the paper of which the tube-sections are composed.

In the accompanying drawings, Figure 1 reprcsenls a longitudinal section of portions of two adjacent and joined tubcsections, with their contained and joined conductors. Fig. 2 is a longitudinal section of a tube-section and its contained conductor-sections suspended in position for pouring in the resin or other substance employed, the portion of the tube and conductors between the ends being broken away; and Fig. 3 represents a picrc of a conductor which I prefer to use, showing the manner of applying the insulation and secondary or induction conductor.

Similar letters of reference designate correspouding parts in all the figures.

A A designate tubesectious, which may be produced in any suitable lengths desired. These tuhesections are each mode of strips of vegetable paper, which are spirally wound and superposed one on another, care being taken to break joints, until the desired thick ness is obtained. These strips are wound spirally under strong tension in a lathe or analogous machine, and an adhesive substance is employed in order that thc superposed layers mogeueons tube. The adhcsivcsubstance employed may be a solution of shellac or any suitable alkaline solution. After the tubesections are thus produced theyare coated inside and outside with bitumen, asphalt, pitch. tar, or any other suitable preservative compound, and are then completed for further use.

B designates a coupling-sleeve. which is of a size to slip on the exterior of the tube-sec tions, and which is or may he made in the same way by spirally winding strips ol' vegetable paper. Tin-so coupling-sleeves may be coated externally and internally in the same manner as the tube-sections.

C designates the conductor-sections, which may be iron or copper win-s, and which are insulated separately,

When a large llllllllJLl' of conductors are to be laid in a tube or conduit, they should be severally provided with secondary or i uduction conductors for the induced current produced by the passage ol' a primary current through the main conductor. The conductor which I prefer to use is the one shown and described in my Letters Patcnt Xo. 304,540, dated September 2, 1884; but I may employ simple condoctors insulated by spirally-wound strips of vegetable paper. A piece of such a. compound couductor is shown in Fig. 1 To the primary conductor a. I apply omor more spirally-wound strips of vegetable paper. I have here shown two strips, b b. These are applied with any suitable adhesive substancesuch, for example, as a solution of shellac or an alkaline solution-and so as to break joints one with another. I then wind on spirally a. third strip, 6', of similar paper, and with and shall adhere and form a strong, solid, and hoinside this I wind on spirally afiue wire or ribbon of metal, 0, which forms the secondary or induction conductor. Outside the strip b is applied another strip, b, and, if desired, a second strip, 1), of similar paper. By this means the primary conductor a is effectively insulated, and the secondary conductor c is insulated both from the primary conductor and externally. The compound conductors thus produced have the insulation as long as the tnbesections A, and the uncovered ends of the conductors will projects considerably beyond the ends of the tube-section when placed therein. The conductor-sections thus produced should be straight, and are laid within a tubesection A, and the whole is then placed in an upright position, as shown in Fig. 2, and suspended.

In order to hold the condnctorsections out of contact with each other, I apply templets or perforated plates D to opposite ends of the tube-section, and the bare ends of the conductor-sections are received through suitablyarrauged perforations in these plates, whereby they are held out of contact with each other and out of contact with the tube A. I then fill the tnbesection with melted resin, asphalt, or other suitable substance or compound through a funnel, E, at the top, and when this has set the conductors are embedded out of contact with each other in a solid mass of :esin, other substance hich will con tribute o the insulation of thecoudnctorgand will penetrate and preserve the paper of which the cover g for the condnrtors and the tube sections are composed.

In laying the tube-sections and their con tained conductor scciions, they are laid at some distance apart. and the primary eondnctors which project from their adjacent ends are joined. as also are the secondary condoctors. The joined ends of the primary and secondary conductors are then properly insulated, and the several conductors are bent or placed out of contact. 01' course the joined ends ofthc conductors require more room than would be attended by the internal area of the tube-sections A; but the room afforded in the coupling-sleeve B is ample to accommodate them. When the conductors are thus properly joined and isolated, a conplingsleevc, B, is slipped on, so as to cover the space between the tube-sections and lap on each. The ends of this coupling-sleeve are then lnted with clay, the ends may have a rabbet, for that. purpose,) and melted parat'fine is poured in through a hole, 0, in the top of the sleeve to fill the whole interior thereof between the adjacent ends of the tube-sections, and thus the 60 joined conductors are embedded in a mass, f,

of parafline. which remains sot't. Other sub stance than paratlinc may be used; but itshould be of snchu nature that it will remain sot't, as the removal of any one section and its contained conductors is thus greatly facilitated.

If it; is desired to remove a tubcsection, the sleeve B is slipped away from the joint, and the conductors are dug out. from the soft paraflineand disconnected. Thetubc-sectionand its contained conductor-sections may thus be removed without, disturbing other sections.

I am aware that it is not. new to make tubes by spirally winding strips of paper and to then out such tubes into proper length to form the bodies of cyliudric boxes; and law also aware that it. is not new to lay a number of simple primary conductors by embedding sections of the conductors in tube-sections composed of wood, the tubeseetions being laid with separated ends and united by a sleeve, and the ends of conductor-sections in adjacent tube sections being joined between the ends of the tube-sections and embedded in insulating material. I do not desire to claim the means of laying and protecting conductors above de scribed as of my invention, nor do I desire to cover, broadly, tubes made of spirally-wound and superposed strips of paper. When conductors have an insulation composed of spi' rally-wound strips oi" vegetable paper and are embedded in insulating material within a tube composed ot'thc same material, the insulating material penetrates and preserves both the paper covering of the conductors and the paper whereof the tube is made, and both the insulatingiilling and the tube combine to form a very perfect insulation ofthe conductors. The combination of conductors so insulated with a tube and filling of the kind described combine to enable me to lay a larger number of wires within a tube of given size and more perfectly insulated than any system of which I have kuowhdge.

What Iclaim as my invention, and desireto secure by Letters Patent, is

The combination, with tube-sections A A, laid with separated ends and composed of spirally-wooed and superposed strips of vegetable paper, and a coupling-sleeve, B, connecting them. ofcondnctor-seetions C, arranged in the tune-sections and each having an insulation ot'spirally-won nd st rips of pure vegetable paper, the conductor-sections being joined between the tube-sections, and a filling of insulating material within the tnbc'sections and coupling-sleeve. and in which the conductorsecbions are embedded. substantially as herein described.

D. McCRACKEi'.

Ilituesses- C. HALL, l-mmn. Hirxrs.

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